Răspuns:
ms=150g
C=20%
md=C×md/100=150×20/100=30gH2SO4
MAl27g/mol
MH2SO4 =2×1+32+4×16=98g/mol
2×27g......3×98g
2Al+ 3H2SO4 => Al2(SO4)3+3H2
xg............30g
x=30×2×27/3×98=5,51g Al
calculăm nr de moli de H2
n=m/M=30/98=0,3 moli H2SO4
3 moli...................................3moli
2Al+ 3H2SO4 => Al2(SO4)3+3H2
0,3moli..............................ymoli
y=3×0,3/3= 0,3 moli H2